police helicopter with special heat- sensing technology spotted the contours of a body in that boat, law enforcement moved in. ( gunfire ) >> reporter: after an hour or more of sporadic gunfire, the suspect, dzhokar tsarnaev, emerged a bloody and bowed 19- year-old lying prone outside the home of dave hennerberry. his stepson, robert duffy: >> and the tarp from the boat was kind of askew. he went over to it, trying to adjust the straps. he realized one of the straps had been cut. at that point, he noticed there was a small amount of blood. he looked forward, not knowing what he was actually looking at. he... his brain told him there was a body, but he wasn't sure there was a body. at that point, he immediately jumped down, called 911. ( cheers and applause ) >> reporter: word that tsarnaev was in custody was cause for celebration. doctors at beth israel deaconess hospital say tsarnaev is in serious condition, under armed guard and unable to speak for now, but a special federal interrogation team for high- value suspects will introduce themselves to him when he improves. governor deval pa